$A$ ball is projected upwards. Its acceleration at the highest point is

$A$ man drops a ball from the roof of a tower of height $400 \ m$. At the same time,another ball is thrown upwards with a velocity of $50 \ m/s$ from the base of the tower. At what height from the base of the tower will they meet (in $m$)?

The nature of a graph drawn for a freely falling body with time on the $x$-axis and speed on the $y$-axis is (Assuming initial speed to be zero.)

$A$ ball is dropped from a bridge that is $45 \ m$ above the water. It falls directly into a boat which is moving with constant velocity. The boat is $12 \ m$ away from the point of impact when the ball is dropped. The speed of the boat is (Take $g=10 \ m \ s^{-2}$) (in $m \ s^{-1}$)

From a building,two balls $A$ and $B$ are thrown such that $A$ is thrown upwards and $B$ is thrown downwards with the same speed $u$ (both vertically). If $v_{A}$ and $v_{B}$ are their respective velocities on reaching the ground,then:

$A$ body falling under gravity covers two points $A$ and $B$ separated by $80 \ m$ in $2 \ s$. The distance of the upper point $A$ from the starting point is (use $g = 10 \ m/s^2$): (in $m$)